Electric coffee maker



March 14, 1939. c D, KEATQN 2,150,801

ELECTRIC COFFEE MAKER Filed Dec. 17, 1937 2 Sheets-Sheet l D L w J 45 INVENTOR 30 144617444;

19 ATTORNEYS March 14, 1939; D KEATQN 2,150,801

ELECTRIC COFFEE MAKER Filed Dec. 17, 1937 2 Sheets-Sheet. 2

IHNVENTOR ATTO R N EYS Patented Mar. 14, 1939 UNITED STATES PATENT OFFICE ELECTRIC COFFEE MAKER Clyde D. Keaton, Long Island City, N. Y., as-

signor to Stanley S. Tumbridge, Brooklyn, N. Y.

Application December 17, 1937, Serial No. 180,263

8 Claims. (01. 219-43) The object of my invention is to provide an the water risesand falls in the lower chamber electric cofiEee maker of the vacuum type in of the coffee pot; which automatic means, under the control of the Fig. 2 represents a similar section through a contents of the coifee pot, is employed to cut oil portion of my invention, showing the parts in pothe heat when the cofiee reaches apredetersition for completion of the circuit to give high 5 mined point in its making and to reestablish a heat in one of the heating elements;

part of the heat after the coffee is made, to Fig. 3 represents a similar section through a maintain the coifee hot as long as desired. portion of my invention, showing the parts in A further object of my invention is to provide position for completion of the circuit through in automatic means for hastening the cooling of the heating unit to give low heat; the electric heating units when the current is cut Fig. 4 represents a similar section through a ofi therefrom. second embodiment of my invention, in which My invention comprises, generally, an electric the rise and fall of steam pressure in the lower cofiee maker in which the lower vessel of the chamber of the coffee pot controls the opening 1! coffee pot is dormed integral with the heater casand closing of the circuit; and ing, and in which the heater is provided with Fig. 5 represents a detail side view of a cena heating chamber having a heating unit theretral section of the air controlling shutters for in, said heating unit comprising a plurality of the heating chamber, in a closed position. heating elements, the circuit through the heat- The coffee pot comprises a lower vessel I, an 2 ing unit being completed to give high heat in one upper vessel 2 nested therein, and a filter 3 of of said elements by the manual closing of a any well known or approved form for establishswitch in the circuit. ing communication between the lower and upper My invention further comprises an electric chambers of said vessel. The upper vessel 2 cofice maker in' which the circuit through the may be provided with a removable cover 4. The :5 heating unit is out 01f when the water in the lower vessel may be provided with a handle 5 lower chamber of the coffee pot is forced upand a pouring spout 6, within which pouring wardly into the upper chamber thereof through spout is seated a weighted valve 1, in the presa filter of well known or approved form. ent instance of the ball type, for preventing the My invention further comprises means whereescape of steam from the lower chamber through I :20 by the circuit is completed through the heating the said spout.

unit togive low heat when the cofiee has been The electric heater casing of the coffee maker drawn back into the lower chamber of the coffee is denoted as a whole by 8, and it is formed inpot to keep the cofiee hot as long as desired. tegral with the lower vessel I of the coffee pot.

My invention also comprises an automatic ven- The top of the heater casing has a heating chamtilator for air cooling the heating unit when the her 9 in which the heating elements III, II, con- 35 circuit therethrough has been broken, said vennected in series, are located.-

tilator being closed when the current is passing Shutters l2 pivoted at l3 serve to open and through the heating unit to give high heat in close the open bottom of this heating chamber one of said heating elements. 9. These shutters are held closed against their My invention still further comprises a cofiee tendency to open by gravity by providing the maker in which a hand lever is used to operate shutters at one side of their pivots l3 with upa switch in the circuit to complete the circuit turned lips 14 engaged by a horizontal plate l5 through the unit to give high heat in one of said connected by an upright rod l6 to a horizonheating elements, said hand lever being under tally disposed hand lever l'l pivoted at l8 on the 5 the control of the contents of the coffee pot for bottom of the heater 8. Said lever ll extends throwing the-lever to open the switch and therethrough a slot [9 in casing 8 to permit manual by open the circuit through the heating unit. operation thereof. A spring 20 tends to lift lever Practical embodiments of my invention are H to the limit of its upward movement against represented in the accompanying drawings, in a stop 2|. This hand lever I1 is releasably held Whichat the limit of its downward movement by an 50 Fig. 1 represents a detail vertical central secelectromagnet 22 and its trip lever 23, which tion through one embodiment of my invention in lever is pivoted at 24 to the bottom of the heater which two spaced terminals are located in the casing 8. This trip lever 23 is provided with a lower chamber of the coffee pot, said terminals shoulder 25 which engages a projection 26 on being electrically connected and disconnected as the hand lever ll when the trip lever 23 is swung 55 to the limit of its forward movement by the energization of the electromagnet 22. A spring 21 serves to swing the lever 22 outwardly when the electromagnet 22 is partially deenergized, to release the projection 22 from the shoulder 2' 01' said trip lever 22.

A switch 28, in the present instance, a mercury switch, is mounted on the hand lever l1 in position to close the circuit through the switch when the hand lever is in its depressed position, and to open the circuit through the switch when said lever is in its raised position.

The main line wire 22 leads into the heater to one coil of the electromagnet 22. The other main line wire 32 leads into the heater to the open terminal 2|. Wire 22 leads from main line wire 22 to heating element It. Wire 33 connects heating elements l and il in series. Wire 22 leads from wire 22 to one terminal of mercury switch 2|. Wire 22 leads from the other terminal of mercury switch 28 back into main line wire 22. Wire 26 leads from wire I! to the opposite end of the coil of electromagnet 22 to which wire 29 is led. Wire 31 leads from heating element II to an open terminal 28. Wires 29 and I, located partially in a recess 44 in handle 5, lead from electrodes ll and 42 respectively, to the second coil of electromagnet 22.

Electrodes ll, 42 are located within the lower chamber of the coflee pot, the electrical circuit at these points being made and broken by the water or liquidcoflee as the case may be, as it rises and falls within the said lower chamber to points above and below the terminals 4| and 42.

A manually operated switch 43 is placed in the main line leading to the heater from .a source of current supply, not shown herein.

In the form shown in Fig. 4, the trip lever 23 for the hand lever I1 is pressure controlled by a pump, the interior of which pump on one side of the piston 46 which is carried by the trip lever 22 is open to pressure within the lower chamber of the coffee pot through the passage 41 which leads from the pump to the upper end of the lower chamber of said coiIee pot. Trip lever 23 carries a piston rod 48 having a contact plate 45 adapted to close the circuit through both elements by contact with terminals Si, 38, to give low heat. The movement of trip lever 23 to complete the circuit through terminals 3!, 38 by means oi contact plate 45 is controlled by suction set-up in the lower chamber of the coffee pot when said lower chamber is cooled after the high heat has been automatically shut off and the ventilator shutters l2 automatically opened. The liquid oofi'ee is drawn back into the lower chamber of the coffee pot through filter 3, when the pressure in said lower chamber is reduced through the cooling of the chamber, as above stated.

In the form shown in Fig. 1, the operation is as follows:

The upper and lower chambers of the coffee pot are supplied with ground cofl'ee and water respectively. The switch 42 in the main supply line is manually closed. This completes the circult through both coils of electromagnet 22, thereby completely energizing same. This causes trip lever 22 to move in against the tension of spring 21 to close open contacts 3|, 28 by means of a contact plate 45 carried by trip lever 23. With the parts in these positions, the circuit is completed through both heating elements in, I I,

connected in series, giving low heat. Hand lever I1 is then depressed and snapped by shoulder of lever 23 in order that said shoulder 25 may releasably engage projection 26 on said lever i1 and hold some in its depressed position. This downward movement of hand lever ll closes shutters l2 and tilts mercury switch 28, closing the circuit therethrough. The circuit will then be completed through wires 28, 32, heating element In, wires 22, 34, mercury switch 28, and wires and 30. (See Fig. 2.)

It will be noted that heating element II will be shunted out since elements I! and II are of substantially equal resistance.

Since practically the entire current load passes through the single heating element l0 only, the water in the lower chamber of the coffee pot will be subjected to the maximum heat obtainable from the arrangement of the heating elements.

After the water has been boiled and a sufficient quantity of it has passed up into the upper chamber through filter 3, the water level will fall below the terminals 42 and ti, thereby opening the circuit across said terminals. This will result in a partial deenergization of electromagnet 22 whose attraction for trip lever 23 will be overcome by the tension of spring 21, thus opening contacts Si, 38. This outward movement of lever 22 will release lever i1 and permit it to swing upwardly through the action of spring 20 to open the shutters l2 and tilt mercury switch 28 to also break the circuit at this point.

When the liquid coflee has flowed through filter 3 from the upper chamber to the lower chamber of the coffee pot until the level of the liquid is raised sufliciently to cover terminals 4| and 42 to close the circuit across them, the circult through electromagnet 22 is completed, trip lever 22 is attracted and contact plate 45 closes the open terminals 2|, 38, thus completing the circuit through both elements (as shown in Fig. 3) to give low heat. This will keep the coflfee hot as long as desired.

In the form shown in Fig. 4, the pump which operates trip lever 22 is controlled by the rise and fall of the fluid pressure within the lower chamber of the coffee pot. Otherwise the operation is quite similar to the operation of the form shown in Figs. 1. 2, and 3.

It is evident that various changes may be re sorted to in the form, construction, and arrangement of the several parts without departing from the spirit and scope of my invention, and therefore I do not wish to limit myself to the particular embodiments herein shown and described.

What I claim is:

1. In an electric cofl'ee maker, a casing having a heating chamber, a heating unit therein, said unit comprising a plurality of-heating elements, a coffee pot, manually operated means for closing the circuit through the heating unit to give high heat in one of said elements, and automatic means controlled by the contents of the cofiee pot for opening the circuit through the heating unit, and for thereafter closing the circuit through the heating unit to give low heat, said automatic means including a pair of spaced terminals in the coffee pot, a switch carried by the hand lever, a. trip lever and an electromagnet for operating it.

2. In an electric cofiee maker, a casing .having a heating chamber, a heating unit therein, said unit comprising a plurality of heating elements, a coffee pot including a lower vessel formed integral with the heater casing, manually operated means for closing the circuit through the heating unit to give high heat in one of said elements, and automatic means cbntrolled by the contents or the access oi air to the heating 'chamber for the coiiee pot for opening the circuit through the heating'unit, and for thereafter closing the circuit through the heating unit to give low heat, said automatic meansincluding a pair of spaced terminals in the cofiee pot, a switch carried by the hand lever, a trip lever and an electromagnet for operating it.

3. In an electric coffee maker, a casing having a heating chamber, a heating unit therein, said unit comprising a plurality of heating elements, a coffee pot, manually operated means for closing the circuit through the heating unit to give high heat in one of said elements, and automatic means controlled by the contents of the coflee pot for opening the circuit through the heating unit, and for thereafter closing the circuit through the heating unit, to give low heat, said automatic means including a switch on the hand lever, a trip lever and a fluid pressure controlled pump for operating it.

4. In an electric cofiee maker, a casing having a heating chamber, aheating unit therein, said unit comprising a plurality of heating elements, a coflee pot including a lower vessel formed integral with the heater casing, manually operated means for osing the circuit through the heating unit to give high heat in one 01' said elements, and

automatic means controlled by the contents of the coflee pot for opening the circuit through the heating unit, and for thereafter closing the the heatingunit to give high heat in one of said 1 elements, and automatic means controlled by the contents of the coffee pot for opening the circuit through the heating unit, and for thereafter closing the circuit through the heating n t to give low heat and also for substantially opening unit comprising a plurality oi heating elements,-

a coffee pot including a lower vessel formed integral with the heater casing, manually Ope ted means for substantially closing the access'ot air circuit through the heating unit to give high heat in one of said elements, and automatic means controlled by the contents of the coffee pot for opening the circuit through the heating unit, and for thereafter closing the circuit through the heating unit to give low heat and also {or substantially opening the access or air to the heating chamber for rapidly cooling it.

'7. In an electric coil'ee maker, a casing having {a heating chamber, a heating unit therein, said unit comprising a pluralityoi "heating elements, a ventilator forthe heating chamber, a coflee pot, manually operated means for closing the ventilator and also for closing the circuit through the heating unit to give high heat in one of said elementaand automatic means controlled by the contents of the coffee pot for opening the circuit through the heating unit, and for thereafter closing the circuit through the heating unit to give low' heat and also for opening the ventilator to rapidly cool the heating chamber.

8. In an electric cofiee maker, a having a heating chamber, a heating unit therein, said unit comprising a plurality of heating elements, a ventilator'tor the heating chamber, a coffee pot, including a lower vessel formed integral with the heaterv casing, manually operated means for closing the ventilator and also for closing the cir-' ber. CLYDE D. KEA'I'ON. 

